X-ray Characterization of Conformational Changes of Human Apo- and Holo-Transferrin
Human serum transferrin (Tf) is a bilobed glycoprotein whose function is to transport iron through receptor‐mediated endocytosis. The mechanism for iron release is pH‐dependent and involves conformational changes in the protein, thus making it an attractive system for possible biomedical application...
| Autores: | , , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2021 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/257107 |
| Acceso en línea: | http://hdl.handle.net/10261/257107 |
| Access Level: | acceso abierto |
| Palabra clave: | Conformation change Human serum transferrin PH‐dependence X‐ray crystallography |
| Sumario: | Human serum transferrin (Tf) is a bilobed glycoprotein whose function is to transport iron through receptor‐mediated endocytosis. The mechanism for iron release is pH‐dependent and involves conformational changes in the protein, thus making it an attractive system for possible biomedical applications. In this contribution, two powerful X‐ray techniques, namely Macromolecular X‐ray Crystallography (MX) and Small Angle X‐ray Scattering (SAXS), were used to study the conformational changes of iron‐free (apo) and iron‐loaded (holo) transferrin in crystal and solution states, respectively, at three different pH values of physiological relevance. A crystallographic model of glycosylated apo‐Tf was obtained at 3.0 Å resolution, which did not resolve further despite many efforts to improve crystal quality. In the solution, apo‐Tf remained mostly globular in all the pH conditions tested; however, the co‐existence of closed, partially open, and open conformations was observed for holo‐Tf, which showed a more elongated and flexible shape overall. |
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